Add invidious companion support

config/config.example.yml

@@ -54,6 +54,44 @@ db:
 ##
 #signature_server:
 
+##
+## Invidious companion is an external program
+## for loading the video streams from YouTube servers.
+##
+## When this setting is commented out, Invidious companion is not used.
+## Otherwise, Invidious will proxy the requests to Invidious companion.
+## 
+## Note: multiple URL can be configured. In this case, invidious will
+## randomly pick one every time video data needs to be retrieved. This
+## URL is then kept in the video metadata cache to allow video playback
+## to work. Once said cache has expired, requesting that video's data
+## again will cause a new companion URL to be picked.
+##
+## The parameter private_url needs to be configured for the internal
+## communication between the companion and Invidious.
+## And public_url is the public URL from which companion is listening
+## to the requests from the user(s).
+## Both parameter can have identical URL when Invidious is hosted in
+## an internal network or at home.
+##
+## Accepted values: "http(s)://<IP-HOSTNAME>:<Port>"
+## Default: <none>
+##
+#invidious_companion:
+#  - private_url: "http://localhost:8282"
+#    public_url: "http://localhost:8282"
+
+##
+## API key for Invidious companion
+## The size of the key needs to be more or equal to 16.
+##
+## Needed when invidious_companion is configured
+##
+## Accepted values: "http(s)://<IP-HOSTNAME>:<Port>"
+## Default: <none>
+##
+
+#invidious_companion_key: "CHANGE_ME!!"
 
 #########################################
 #

src/invidious/config.cr

@@ -67,6 +67,16 @@ end
 class Config
   include YAML::Serializable
 
+  class CompanionConfig
+    include YAML::Serializable
+
+    @[YAML::Field(converter: Preferences::URIConverter)]
+    property private_url : URI = URI.parse("")
+
+    @[YAML::Field(converter: Preferences::URIConverter)]
+    property public_url : URI = URI.parse("")
+  end
+
   # Number of threads to use for crawling videos from channels (for updating subscriptions)
   property channel_threads : Int32 = 1
   # Time interval between two executions of the job that crawls channel videos (subscriptions update).
@@ -151,6 +161,12 @@ class Config
   # poToken for passing bot attestation
   property po_token : String? = nil
 
+  # Invidious companion
+  property invidious_companion : Array(CompanionConfig) = [] of CompanionConfig
+
+  # Invidious companion API key
+  property invidious_companion_key : String = ""
+
   # Saved cookies in "name1=value1; name2=value2..." format
   @[YAML::Field(converter: Preferences::StringToCookies)]
   property cookies : HTTP::Cookies = HTTP::Cookies.new
@@ -222,6 +238,24 @@ class Config
         end
     {% end %}
 
+    if !config.invidious_companion.empty?
+      # invidious_companion and signature_server can't work together
+      if config.signature_server
+        puts "Config: You can not run inv_sig_helper and invidious_companion at the same time."
+        exit(1)
+      end
+      if config.invidious_companion_key.empty?
+        puts "Config: Please configure a key if you are using invidious companion."
+        exit(1)
+      elsif config.invidious_companion_key == "CHANGE_ME!!"
+        puts "Config: The value of 'invidious_companion_key' needs to be changed!!"
+        exit(1)
+      elsif config.invidious_companion_key.size < 16
+        puts "Config: The value of 'invidious_companion_key' needs to be a size of 16 or more."
+        exit(1)
+      end
+    end
+
     # HMAC_key is mandatory
     # See: https://github.com/iv-org/invidious/issues/3854
     if config.hmac_key.empty?

src/invidious/helpers/utils.cr

@@ -383,3 +383,22 @@ def parse_link_endpoint(endpoint : JSON::Any, text : String, video_id : String)
   end
   return text
 end
+
+def encrypt_ecb_without_salt(data, key)
+  cipher = OpenSSL::Cipher.new("aes-128-ecb")
+  cipher.encrypt
+  cipher.key = key
+
+  io = IO::Memory.new
+  io.write(cipher.update(data))
+  io.write(cipher.final)
+  io.rewind
+
+  return io
+end
+
+def invidious_companion_encrypt(data)
+  timestamp = Time.utc.to_unix
+  encrypted_data = encrypt_ecb_without_salt("#{timestamp}|#{data}", CONFIG.invidious_companion_key)
+  return Base64.urlsafe_encode(encrypted_data)
+end

src/invidious/routes/api/manifest.cr

@@ -8,6 +8,11 @@ module Invidious::Routes::API::Manifest
     id = env.params.url["id"]
     region = env.params.query["region"]?
 
+    if !CONFIG.invidious_companion.empty?
+      invidious_companion = CONFIG.invidious_companion.sample
+      return env.redirect "#{invidious_companion.public_url}/api/manifest/dash/id/#{id}?#{env.params.query}"
+    end
+
     # Since some implementations create playlists based on resolution regardless of different codecs,
     # we can opt to only add a source to a representation if it has a unique height within that representation
     unique_res = env.params.query["unique_res"]?.try { |q| (q == "true" || q == "1").to_unsafe }

src/invidious/routes/embed.cr

@@ -201,6 +201,13 @@ module Invidious::Routes::Embed
       return env.redirect url
     end
 
+    if companion_base_url = video.invidious_companion.try &.["baseUrl"].as_s
+      env.response.headers["Content-Security-Policy"] =
+        env.response.headers["Content-Security-Policy"]
+          .gsub("media-src", "media-src #{companion_base_url}")
+          .gsub("connect-src", "connect-src #{companion_base_url}")
+    end
+
     rendered "embed"
   end
 end

src/invidious/routes/video_playback.cr

@@ -253,6 +253,11 @@ module Invidious::Routes::VideoPlayback
   # YouTube /videoplayback links expire after 6 hours,
   # so we have a mechanism here to redirect to the latest version
   def self.latest_version(env)
+    if !CONFIG.invidious_companion.empty?
+      invidious_companion = CONFIG.invidious_companion.sample
+      return env.redirect "#{invidious_companion.public_url}/latest_version?#{env.params.query}"
+    end
+
     id = env.params.query["id"]?
     itag = env.params.query["itag"]?.try &.to_i?
 

src/invidious/routes/watch.cr

@@ -190,6 +190,13 @@ module Invidious::Routes::Watch
       captions: video.captions
     )
 
+    if companion_base_url = video.invidious_companion.try &.["baseUrl"].as_s
+      env.response.headers["Content-Security-Policy"] =
+        env.response.headers["Content-Security-Policy"]
+          .gsub("media-src", "media-src #{companion_base_url}")
+          .gsub("connect-src", "connect-src #{companion_base_url}")
+    end
+
     templated "watch"
   end
 
@@ -320,14 +327,18 @@ module Invidious::Routes::Watch
       env.params.query["label"] = URI.decode_www_form(label.as_s)
 
       return Invidious::Routes::API::V1::Videos.captions(env)
-    elsif itag = download_widget["itag"]?.try &.as_i
+    elsif itag = download_widget["itag"]?.try &.as_i.to_s
       # URL params specific to /latest_version
       env.params.query["id"] = video_id
-      env.params.query["itag"] = itag.to_s
       env.params.query["title"] = filename
       env.params.query["local"] = "true"
 
-      return Invidious::Routes::VideoPlayback.latest_version(env)
+      if (!CONFIG.invidious_companion.empty?)
+        video = get_video(video_id)
+        return env.redirect "#{video.invidious_companion["baseUrl"].as_s}/latest_version?#{env.params.query}"
+      else
+        return Invidious::Routes::VideoPlayback.latest_version(env)
+      end
     else
       return error_template(400, "Invalid label or itag")
     end

src/invidious/videos.cr

@@ -15,7 +15,7 @@ struct Video
   # NOTE: don't forget to bump this number if any change is made to
   # the `params` structure in videos/parser.cr!!!
   #
-  SCHEMA_VERSION = 2
+  SCHEMA_VERSION = 3
 
   property id : String
 
@@ -192,6 +192,10 @@ struct Video
     }
   end
 
+  def invidious_companion : Hash(String, JSON::Any)?
+    info["invidiousCompanion"]?.try &.as_h || {} of String => JSON::Any
+  end
+
   # Macros defining getters/setters for various types of data
 
   private macro getset_string(name)

src/invidious/videos/parser.cr

@@ -100,30 +100,32 @@ def extract_video_info(video_id : String)
   params = parse_video_info(video_id, player_response)
   params["reason"] = JSON::Any.new(reason) if reason
 
-  new_player_response = nil
-
-  # Don't use Android test suite client if po_token is passed because po_token doesn't
-  # work for Android test suite client.
-  if reason.nil? && CONFIG.po_token.nil?
-    # Fetch the video streams using an Android client in order to get the
-    # decrypted URLs and maybe fix throttling issues (#2194). See the
-    # following issue for an explanation about decrypted URLs:
-    # https://github.com/TeamNewPipe/NewPipeExtractor/issues/562
-    client_config.client_type = YoutubeAPI::ClientType::AndroidTestSuite
-    new_player_response = try_fetch_streaming_data(video_id, client_config)
-  end
+  if !CONFIG.invidious_companion.empty?
+    new_player_response = nil
+
+    # Don't use Android test suite client if po_token is passed because po_token doesn't
+    # work for Android test suite client.
+    if reason.nil? && CONFIG.po_token.nil?
+      # Fetch the video streams using an Android client in order to get the
+      # decrypted URLs and maybe fix throttling issues (#2194). See the
+      # following issue for an explanation about decrypted URLs:
+      # https://github.com/TeamNewPipe/NewPipeExtractor/issues/562
+      client_config.client_type = YoutubeAPI::ClientType::AndroidTestSuite
+      new_player_response = try_fetch_streaming_data(video_id, client_config)
+    end
 
-  # Replace player response and reset reason
-  if !new_player_response.nil?
-    # Preserve captions & storyboard data before replacement
-    new_player_response["storyboards"] = player_response["storyboards"] if player_response["storyboards"]?
-    new_player_response["captions"] = player_response["captions"] if player_response["captions"]?
+    # Replace player response and reset reason
+    if !new_player_response.nil?
+      # Preserve captions & storyboard data before replacement
+      new_player_response["storyboards"] = player_response["storyboards"] if player_response["storyboards"]?
+      new_player_response["captions"] = player_response["captions"] if player_response["captions"]?
 
-    player_response = new_player_response
-    params.delete("reason")
+      player_response = new_player_response
+      params.delete("reason")
+    end
   end
 
-  {"captions", "playabilityStatus", "playerConfig", "storyboards"}.each do |f|
+  {"captions", "playabilityStatus", "playerConfig", "storyboards", "invidiousCompanion"}.each do |f|
     params[f] = player_response[f] if player_response[f]?
   end
 

src/invidious/views/components/player.ecr

@@ -22,6 +22,8 @@
                audio_streams.each_with_index do |fmt, i|
                 src_url  = "/latest_version?id=#{video.id}&itag=#{fmt["itag"]}"
                 src_url += "&local=true" if params.local
+                src_url = video.invidious_companion["baseUrl"].as_s + src_url + 
+                            "&check=#{invidious_companion_encrypt(video.id)}" if (!CONFIG.invidious_companion.empty?)
 
                 bitrate = fmt["bitrate"]
                 mimetype = HTML.escape(fmt["mimeType"].as_s)
@@ -34,8 +36,12 @@
                 <% end %>
             <% end %>
         <% else %>
-            <% if params.quality == "dash" %>
-                <source src="/api/manifest/dash/id/<%= video.id %>?local=true&unique_res=1" type='application/dash+xml' label="dash">
+            <% if params.quality == "dash"
+               src_url = "/api/manifest/dash/id/" + video.id + "?local=true&unique_res=1"
+               src_url = video.invidious_companion["baseUrl"].as_s + src_url +
+                            "&check=#{invidious_companion_encrypt(video.id)}" if (!CONFIG.invidious_companion.empty?)
+            %>
+                <source src="<%= src_url %>" type='application/dash+xml' label="dash">
             <% end %>
 
             <%
@@ -44,6 +50,8 @@
             fmt_stream.each_with_index do |fmt, i|
                 src_url  = "/latest_version?id=#{video.id}&itag=#{fmt["itag"]}"
                 src_url += "&local=true" if params.local
+                src_url = video.invidious_companion["baseUrl"].as_s + src_url +
+                            "&check=#{invidious_companion_encrypt(video.id)}" if (!CONFIG.invidious_companion.empty?)
 
                 quality = fmt["quality"]
                 mimetype = HTML.escape(fmt["mimeType"].as_s)

src/invidious/yt_backend/youtube_api.cr

@@ -500,7 +500,11 @@ module YoutubeAPI
       data["params"] = params
     end
 
-    return self._post_json("/youtubei/v1/player", data, client_config)
+    if !CONFIG.invidious_companion.empty?
+      return self._post_invidious_companion("/youtubei/v1/player", data)
+    else
+      return self._post_json("/youtubei/v1/player", data, client_config)
+    end
   end
 
   ####################################################################
@@ -666,6 +670,51 @@ module YoutubeAPI
     return initial_data
   end
 
+  ####################################################################
+  # _post_invidious_companion(endpoint, data)
+  #
+  # Internal function that does the actual request to Invidious companion
+  # and handles errors.
+  #
+  # The requested data is an endpoint (URL without the domain part)
+  # and the data as a Hash object.
+  #
+  def _post_invidious_companion(
+    endpoint : String,
+    data : Hash
+  ) : Hash(String, JSON::Any)
+    headers = HTTP::Headers{
+      "Content-Type"  => "application/json; charset=UTF-8",
+      "Authorization" => "Bearer #{CONFIG.invidious_companion_key}",
+    }
+
+    # Logging
+    LOGGER.debug("Invidious companion: Using endpoint: \"#{endpoint}\"")
+    LOGGER.trace("Invidious companion: POST data: #{data}")
+
+    # Send the POST request
+
+    begin
+      invidious_companion = CONFIG.invidious_companion.sample
+      response = make_client(invidious_companion.private_url,
+        &.post(endpoint, headers: headers, body: data.to_json))
+      body = response.body
+      if (response.status_code != 200)
+        raise Exception.new(
+          "Error while communicating with Invidious companion: \
+          status code: #{response.status_code} and body: #{body.dump}"
+        )
+      end
+    rescue ex
+      raise InfoException.new("Error while communicating with Invidious companion: " + (ex.message || "no extra info found"))
+    end
+
+    # Convert result to Hash
+    initial_data = JSON.parse(body).as_h
+
+    return initial_data
+  end
+
   ####################################################################
   # _decompress(body_io, headers)
   #